A Vaillant condensing boiler is equipped with a filter that is easy to assemble and perfectly compatible with the fittings and pipes. To ensure the durability of the neutralizing spheres included in the filter, it’s recommended to perform an annual replacement. However, this may be shortened in the presence of “dirtier” calcareous water.
A visual indicator of the filter’s condition is the color of the balls inside the plastic cylinder. If they become completely dark or reddish, it’s time to empty them and replace them with new ones.